Development of force adaptation during childhood

Abstract

ABSTRACT. Humans learn to make reaching movements 1n novel dynamic environments by acquiring an internal motor model of their limb dynamics. Here, the authors investigated how 4- to ll-year-old children (N = 39) and adults (N = 7) adapted to changes in arm dynamics, and they examined whether those data ruppö.t the view that the human brain acquires inverse dynamics möd"ls (IDM) during development. While external damping forces were applied, the children leamed to perform goal-directed forearm flexion movements. After changes in damping ' all chil-dren showed kinematic aftereffects indicative of a neural con-troller that still attempted to compensate the no longer existing damping force. With increasing age, the number of trials toward co-plei " adaptation decreased. When damping was present ' fore-arm paths were most perturbed and most variable in the youngest children but were improved in the older children. The finding